In automobiles, the volumes of in-car communication traffic have increased with an increase in in-car electrical components. Thus, in order to cope with the increased volumes of in-car communication traffic, measures to shift in-car communication media of electric wires to fiber-optic cables that include optical fibers and are capable of transmitting larger volumes of data at higher speed than the electric wires have been taken.
Optical connectors are used for connecting the fiber-optic cables, or connecting the fiber-optic cable and an optical transmitter and receiver module mounted on a circuit board. In carrying out wiring of the fiber-optic cables in an automobile, the fiber-optic cables could be pulled to apply tension between the fiber-optic cables and the optical connectors. Thus, the optical connectors, in particular, optical connectors for automobile use, are required to be tightly connected to the fiber-optic cables. In addition, relatively short fiber-optic cables for automobile or interior use usually have a configuration such that tensile members such as optical fibers and aramid fibers are laid in the center and covered with a sheath for protection. While the tensile members bear the tensile strength of the whole fiber-optic cables, what is directly pulled by a worker in actual wiring is the sheath when the worker pulls the fiber-optic cables. In this case, because the tensile members and the sheath are not of a monolithic construction, only the sheath could falloff the optical connector even if the tensile members are fixed to the optical connector with sufficient strength. In order to solve this problem, both the tensile members and the sheath need to be fixed to the optical connector.
The configuration disclosed in PTL 1 is proposed as a connecting structure between a fiber-optic cable and an optical connector, and is in widespread practical use. PTL 1 discloses an optical connector, in which a tensile member of a fiber-optic cable is sandwiched by a rear portion of a stopper for holding a ferrule, and a large diameter portion of a crimp ring while an end portion of a sheath of the fiber-optic cable is sandwiched by a small diameter portion of the crimp ring and a ring. This configuration prevents the optical connector from falling off the fiber-optic cable.
However, because the optical cable connector of PTL 1 has the configuration that the tensile member and the sheath are sandwiched by the different members, there arises a problem that the numbers of components and processes increase. In order to solve this problem, the configuration disclosed in PTL 2 is proposed, for example. PTL 2 discloses an optical connector that includes a thick cord cover (sheath), so that the cord cover itself functions as a crimping base (corresponding to the small diameter portion of the crimp ring of PTL 1). Thus, the numbers of components and processes are reduced. The configuration of PTL 2 is advantageous when a connected portion between a fiber-optic cable and the optical connector is desired to be short. In addition, because the prerequisite thick sheath can strengthen the fiber-optic cable, the configuration of PTL 2 is favorable for the fiber-optic cable used in automobiles where the fiber-optic cable is laid together with other wiring harnesses densely in a narrow space. However, because a crimping base is not used, the configuration could not obtain sufficient fixing strength of the sheath.